1. Field of the Invention
The present invention generally relates to computer apparatus and, in a preferred embodiment thereof, more particularly relates to apparatus for dissipating operating heat from a portable computer operatively connected to a docking station used to electrically connect the docked computer to desktop peripheral devices.
2. Description of Related Art
With the advancement of computer microprocessor technology, portable computers such as the increasingly popular notebook computer are beginning to equal larger is desktop computers in performance. The more advanced notebook computers also produce, in quite a small spatial envelope, a very significant amount of operating heat which approaches that generated in a desktop computer and provides the computer designer with the challenging task of sufficiently dissipating the operating heat in order to avoid undesirably high temperatures within the interior of the notebook computer and on its various external surface areas.
Many modern notebook computers are typically operated in three modes--(1) by itself under internal battery power, (2) by itself using converted DC electrical power from an AC electrical source, or (3) operatively connected (or "docked") to a docking station expansion base structure which electrically couples the docked portable computer to desktop peripheral devices such as a monitor, mouse and keyboard.
In the first two of these operating modes the display screen lid portion of the notebook computer is opened, thereby increasing the total exterior surface area of the computer exposed to ambient air to which computer operating heat may be dissipated. When the notebook computer is coupled to the docking station, however, the computer's display screen lid is closed, thereby reducing the overall exposed exterior computer surface area from which heat may be dissipated. This tends to appreciably increase the interior and exterior operating temperatures of the docked computer compared to applications in which it operated by itself with its display screen lid in its opened orientation. Such operating temperature increases are aggravated by the fact that the docking station physically covers and insulates large exterior portions of the docked computer and inhibits the dissipation of heat therefrom.
As an example, a modern high speed notebook computer microprocessor can generate within the computer on the order of about 8 watts when the computer is in its battery mode, about 10-12 watts when the computer is in its AC mode, and up to about 20 watts when the computer is A operatively coupled to a docking station.
Of course, from an operating heat dissipation standpoint, provisions must be made to handle the maximum heat load condition--i.e., when the notebook computer is docked with its lid closed. This has proven to be an extremely challenging design task since the small spatial envelope of modern notebook computer as a practical matter precludes the use therein of traditional desktop computer cooling apparatus such as large internal fans and heat sinks.
A need thus exists for apparatus which will adequately dissipate the substantially increased operating heat generated by a docked portable notebook computer. It is to this need that the present invention is directed.